JPS623244Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a printing method in which an ink ribbon is guided between a printing head placed on a carriage and a paper feeding path, and printing is performed while the carriage is moved parallel to the platen. The present invention relates to machines, and in particular to a device for preventing paper from being smudged by an ink ribbon.

Conventionally, in printing machines such as those mentioned above, especially dot printers, the front of the printing head and the paper are brought close to each other in order to perform high-speed and clear printing. may come in contact with the ink ribbon and stain it.
To prevent this, it is necessary to interpose a ribbon mask between the paper and the ink ribbon, but for example, in a configuration where the front end surface of the print head and this ribbon mask are in close contact, it is necessary to press the ribbon mask with your finger. However, since the ink ribbon must be removed from the inserted ink ribbon, which makes the task of replacing the ink ribbon troublesome, the ribbon mask 5 is formed into a substantially L-shaped plate as shown in FIG. 2, and as shown in FIG. The bottom part 5b is fixed to the lower surface of the print head 2, and the upright part 5a is slightly inclined toward the platen 1 in advance to provide a gap between the upright part 5a and the front end surface of the print head 2, and the ink ribbon 3 is attached and removed. However, in order to reduce the thickness of the ribbon mask 5 in order to reduce cost and load, the ribbon mask 5 becomes more flexible and the print head 2 moves parallel to the platen 1 as the carriage moves. At this time, due to the inertial force of this movement, as shown in FIG. 3, the upright part oscillates in the direction opposite to the movement direction A as shown by the chain line, and the correspondence between the hole 5d and the printing wire 6 is misaligned, causing the ribbon mask to 5 and the printing wire 6 engage with each other, resulting in damage to the wire, etc., and printing becomes unclear, resulting in a decrease in printing quality. In addition, if the hole 5d is enlarged to prevent this, paper will easily enter the hole 5d, resulting in disadvantages such as a reduction in the stain prevention effect of the ribbon mask 5.Furthermore, in order to suppress the flexibility of the ribbon mask 5, the ribbon When the thickness of the mask 5 is increased, the pressing force against the paper 4 when the raised portion 5a of the ribbon mask 5 comes into contact with the platen 1 increases, and the paper 4 is
This was the cause of uneven feeding because it prevented feeding.

This invention aims to eliminate these drawbacks with a simple configuration.

An embodiment of this invention will be described below with reference to FIGS. 4, 5, and 6.

In addition, the same numbers are attached to the parts in the figure that overlap with those in FIG. 1, and the explanation is omitted. Reference numeral 5 designates a ribbon mask, which is made of a bent elastic thin plate as shown in FIG. establish. Furthermore, the standing portion 5a and the bottom portion 5b
A coil spring 7 having a predetermined diameter is fitted and supported in the arc-shaped bent portion 5c between The bottom portion 5b is fixed to the lower end of the print head 2 so as to be held between the bent portion 5c of the mask 5 and the lower end of the print head 2.

In the above configuration, the ink ribbon 3 is inserted between the front end surface of the print head 2 and the upright portion 5a of the ribbon mask 5, the paper 4 is sent between the platen 1 and the ribbon mask 5, and the print head 2 is placed on the ink ribbon 3. When printing is performed by applying the printing wire 6 of the printing head 2 while moving the placed carriage (not shown) parallel to the platen 1, the ribbon mask 5 is thin and has great flexibility. Due to the inertial force caused by the movement of the printing head 2 along with the carriage, the upright portion 5a of the ribbon mask 5 is laterally swung in the opposite direction to the carriage movement direction A (Fig. 6), that is, clockwise in Fig. 6. As a result, the left end (Fig. 6) of the coil spring 7 between the bent portion 5c of the ribbon mask 5 and the lower end of the printing head is pressed in the radial direction by the bent portion 5c of the ribbon mask 5. , the coil spring 7 exerts a force F on the upright portion 5a of the ribbon mask 5, and the horizontal swing of the upright portion 5a is suppressed. Moreover, at this time, since the ribbon mask 5 is thin, its standing portion 5a
The pressing force against the paper 4 when it comes into contact with the platen 1 is not large.

As described above, according to this invention, a substantially L-shaped ribbon mask having an upright part and a bottom part is formed of a thin material, and a coil is placed between the bent part of the ribbon mask and the lower end of the printing head. Since the spring is interposed so that its extension direction is parallel to the ribbon mask, the pressing force on the paper by the upright part is reduced and uneven paper feeding is prevented, and the radial elastic force of the coil spring It becomes possible to suppress the lateral movement of the standing portion and prevent the print from being chipped, which has the effect of simultaneously eliminating two conventionally contradictory drawbacks and improving the print quality.

It should be noted that the coil spring in the above embodiments is not limited to this as long as it is an elastic body, and for example, hard rubber, plate springs, etc. may be used.

Further, in the above embodiment, the wire impact method is shown, but the invention is not limited to this as long as the print head moves while guiding the ribbon. For example, this invention can be similarly applied to a hammer embossing method. I can do it.

[Brief explanation of drawings]

Fig. 1 is a side view of a conventional printing machine, Fig. 2 is a perspective view of a conventional mask, Fig. 3 is a diagram showing the horizontal swing of the upright part of the mask, and Fig. 4 is a diagram of the printing machine according to this invention. 5 is a side view, FIG. 5 is a perspective view of the ribbon mask according to this invention, and FIG. 6 is a diagram showing the action of a coil spring disposed at the bottom of the ribbon mask. Platen...1, Print head...2, Ribbon mask...5, Elastic body (coil spring)...
7.

Claims (1)

[Claims for Utility Model Registration] The front end surface is placed opposite the platen across the paper feeding path, an ink ribbon is interposed between the front end surface and the paper, and the front end surface is moved parallel to the platen. a print head that performs printing by applying a printing member while moving the print head; a bottom portion made of a flexible member and fixed to the lower end surface of the print head; In a printing machine that has a ribbon mask consisting of an upright part provided with a hole through which the printing member passes, an elastic body is attached to the printing head to provide an elastic force that resists rocking displacement of the upright part of the ribbon mask in a direction parallel to the platen. A stain prevention device for a printing machine characterized by being sandwiched between the lower end surface and the bent surface of a ribbon mask.